Redirect From Pretty URL to .html URL - html

Question

I have recently switched from using Wordpress to a static html only site. When I remade each page (there are only 6 pages total) I kept the same URL name.
Example: https://reactiongaming.us/alteriwnet/ is now https://reactiongaming.us/alteriwnet.html
My issues is that old links and Google search results contain the reactiongaming.us/alteriwnet/ version which results in a 404 error. I have tried various .htaccess methods for "pretty URLs but none worked. Usually, these questions were asked on how to redirect from a .html URL to a pretty URL, but I'm trying to do the opposite.
There are only 6 URLs I need to redirect in total from reactiongaming.us/example/ to reactiongaming.us/example.html. Is there an .htaccess or other method to achieve this?
I have tried:
RewriteCond %{THE_REQUEST} \.html [NC]
RewriteRule ^(.*)\.html$ /$1 [R=302,L]
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME}\.html -f
RewriteRule ^(.*)$ $1.html [L]
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^.]+)$ $1.html [NC,L]

Answer 1

You can use Redirect directive to redirect your old URLs to the new URL format
Redirect 301 /alteriwnet/ /alteriwnet.html
This will 301 redirect /alteriwnet to /alteriwnet.html .
To redirect multiple URLs with just a one liner code you can use RedirectMatch which uses a regex based pattern
RedirectMatch 301 ^/(alteriwnet|path2|path3)/?$ /$1.html
References :
Redirect directive
https://httpd.apache.org/docs/2.4/mod/mod_alias.html#redirect
RedirectMatch directive
https://httpd.apache.org/docs/2.4/mod/mod_alias.html#redirectMatch